In which direction do substances move in and out of a cell membrane during active transport? A. From low concentration to low concentration B. From high concentration to low concentration C. From high concentration to high concentration D. From low concentration to high concentration

D. From low concentration to high concentration

Explanation:

Molecules and substances move in and out of living cells via the cell membrane, which act as the semi-permeable membrane. Ideally, substances move from a region where they are highly concentrated to a region where they are low in concentration. This type of transport is called passive transport.

However, another type of transport called ACTIVE TRANSPORT occurs where substances move from a region where they are low in concentration to a region where they are high in concentration. This type of transport occurs against the concentration gradient between the cell membrane and the extracellular solution. Hence, it requires energy in form of ATP to occur.

This kind of transport described above is called ACTIVE TRANSPORT, and it requires energy input because it occurs against concentration gradient i.e. from low concentration of substance to high concentration.

organ system-an organ system is a group of organs that work together to perform one or more functions. each does a particular job in the body, and is made up of certain tissues.